Friday, 11 February 2011

Prestige oil spill far worse than thought

The oil spill from the tanker Prestige, which sank off Spain in November 2002, has been far worse than previously claimed, the Spanish government has disclosed. Environmentalists are now comparing the damage caused to that of the Exxon Valdez disaster in Alaska in 1989.

More than 80 per cent of the tanker's 77,000 tonnes of fuel oil is now thought to have been spilled off Spain's north-east coast. The government initially said just 17,000 tonnes had been lost, adding that the other 60,000 tonnes would freeze and not leak from the sunken tanker.

But earlier in 2003, it announced that half of the oil had been lost, and now that figure has risen to about 63,000 tonnes.

"The environmental devastation caused is at least on a par, if not worse, than the Exxon Valdez," says Simon Walmsley, WWF's senior policy officer for shipping. "The amount of oil spilled is more than the Valdez and the toxicity is higher, because of the higher temperature." The Exxon Valdez spill occurred in extremely cold water, although this also meant it was slower to disperse.

Experts predict marine life will suffer pollution from the Prestige for at least 10 years due to the type of oil spilt, which contain light fractions called polyaromatic-hydrocarbons. These toxic chemicals poison plankton, fish eggs and crustaceans, leading to carcinogenic effects in fish and other animals higher in the food chain.

Robot repairs

The Greek-operated, single-hulled tanker was flying a Bahamas flag, had a Liberian owner and had been chartered by a Swiss-based Russian oil company. In November 2002, in what became Spain's worst environmental disaster, it split into two parts and sank 150 miles off the Galician coast of Spain. More than 1000 beaches across Spain and France have been polluted and the local fishing industry was destroyed in the disaster.

Engineers have spent the past months using robots to seal cracks in the tanker's hull, now 4000 metres below the sea surface. The oil leakage is now reported to have slowed to a trickle of 20 litres a day. By October 2004, engineers hope to have removed the oil still in the tanker. This will be done by drilling of small holes in the wreck, and pumping it out into bags, 250 tonnes at a time. These will be floated to the surface, at a total estimated cost of $100 million.

A recent report by the Galicia-based Barrie de la Maza economic institute criticised the Spanish government's handling of the catastrophe. It estimated the cost of the clean-up to the Galician coast alone at $2.8 billion. The Exxon Valdez clean-up cost $2 billion.

The government was also slated for its decision to tow the ailing wreck out to sea - where it split in two - rather than into a port. But Walmsley believes most of the blame lies with the ship's inspectors who allowed the Prestige to sail. "It was reported as being substandard at one of the ports it visited before Spain. The whole inspection regime needs to be revamped and double-hulled tankers used instead," he says.